What is 28+14?
42
What is 89-21?
68
What is 42+12?
54
What is 67-67?
Easy, 0
What is 13+13?
26
What is 56-22?
34
What is 15+16?
31
What is 78-28?
50
What is 38+39?
77
What is 90-40?